Which of the following contain both ionic and covalent bonds?
A. NaOH
B. KCN
C. Na2SO4
D. All of these
The correct answer and explanation is:
Correct Answer: D. All of these
Explanation (300 words):
To determine which compounds contain both ionic and covalent bonds, we need to understand the nature of these bond types:
- Ionic bonds occur between metals and non-metals where electrons are transferred, forming ions (e.g., Na⁺ and OH⁻).
- Covalent bonds occur when non-metals share electrons (e.g., O–H within OH⁻ or S–O within SO₄²⁻).
Let’s analyze each option:
A. NaOH (Sodium hydroxide):
- Ionic bond between Na⁺ (a metal) and OH⁻ (a polyatomic ion).
- Within the OH⁻ group, O and H are both non-metals and are covalently bonded.
- ✅ Contains both ionic and covalent bonds.
B. KCN (Potassium cyanide):
- Ionic bond between K⁺ (a metal) and CN⁻ (a polyatomic ion).
- Within the CN⁻ ion, carbon (C) and nitrogen (N) are both non-metals and are covalently bonded.
- ✅ Contains both ionic and covalent bonds.
C. Na₂SO₄ (Sodium sulfate):
- Ionic bond between Na⁺ ions and SO₄²⁻ (the sulfate ion).
- Within the SO₄²⁻ ion, sulfur (S) and oxygen (O) are all non-metals and form covalent bonds.
- ✅ Contains both ionic and covalent bonds.
Conclusion:
Each of these compounds consists of:
- Ions held together by ionic bonds, and
- Polyatomic ions with internal covalent bonds.
Therefore, the correct answer is:
✅ D. All of these contain both ionic and covalent bonds.